Question

how can I set scroll of scrollview to x pixels, before it’s even shown?

In ScrollView I have some Views and i know that it will fill screen. Can I scroll to let say second View, so that first View is not visible when activity is started?

Now I have sth like this, but I think it’s not perfect, sometimes, I see first View, and then it’s scrolled to the second one

@Override
public void onGlobalLayout() {
    if (mHorizontalScrollView.getChildCount() > 0 && mHorizontalScrollView.getChildAt(0).getWidth() > mScreenWidth) {
            hsv.scrollTo(100, 0);
    }
}

EDIT!!

Second attempt was to use http://developer.android.com/reference/android/view/ViewTreeObserver.OnPreDrawListener.html instead of http://developer.android.com/reference/android/view/ViewTreeObserver.OnGlobalLayoutListener.html
In OnPreDrawListener we can read that At this point, all views in the tree have been measured and given a frame. Clients can use this to adjust their scroll bounds or even to request a new layout before drawing occurs. so basically at this point we should adjust scrolling. So I created:

@Override
public boolean onPreDraw() {
    if (hsv.getChildCount() > 0 && hsv.getChildAt(0).getWidth() > mScreenWidth) {
        hsv.scrollTo(100, 0);
        return false;
    }
    return true;
}

but now it’s never working for me.

Answer 1

I combined onGlobalLayout with code below. It’s not so great to use that hack but it still quite efficient. When I get onGlobalLayout event I check if layouts are done and then if it’s ok I use method below.

// hsv - horizontal scroll view
private void forceShowColumn(final int column) {
    int scrollTo = childViewWidth * column;
    if (scrollTo == hsv.getScrollX()) {
        return;
    }
    hsv.scrollTo(scrollTo, 0);

    hsv.postDelayed(new Runnable() {

        @Override
        public void run() {
            forceShowColumn(column);
        }
    }, 10);
}